.TH  CLA_GEAMV 1 "November 2008" "    LAPACK routine (version 3.2)                                 " "    LAPACK routine (version 3.2)                                 " 
.SH NAME
CLA_GEAMV - performs one of the matrix-vector operations   y := alpha*abs(A)*abs(x) + beta*abs(y),
.SH SYNOPSIS
.TP 21
SUBROUTINE CLA_GEAMV
( TRANS, M, N, ALPHA, A, LDA, X, INCX, BETA,
Y, INCY )
.TP 21
.ti +4
IMPLICIT
NONE
.TP 21
.ti +4
REAL
ALPHA, BETA
.TP 21
.ti +4
INTEGER
INCX, INCY, LDA, M, N
.TP 21
.ti +4
INTEGER
TRANS
.TP 21
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COMPLEX
A( LDA, * ), X( * )
.TP 21
.ti +4
REAL
Y( * )
.SH PURPOSE
CLA_GEAMV  performs one of the matrix-vector operations
   or   y := alpha*abs(A)\(aq*abs(x) + beta*abs(y),
.br
where alpha and beta are scalars, x and y are vectors and A is an
m by n matrix.
.br
This function is primarily used in calculating error bounds.
To protect against underflow during evaluation, components in
the resulting vector are perturbed away from zero by (N+1)
times the underflow threshold.  To prevent unnecessarily large
errors for block-structure embedded in general matrices,
.br
"symbolically" zero components are not perturbed.  A zero
entry is considered "symbolic" if all multiplications involved
in computing that entry have at least one zero multiplicand.
.SH ARGUMENTS
.TP 7
TRANS  - INTEGER
On entry, TRANS specifies the operation to be performed as
follows:
.TP 19
BLAS_NO_TRANS      y := alpha*abs(A)*abs(x) + beta*abs(y)
.br
BLAS_TRANS         y := alpha*abs(A\(aq)*abs(x) + beta*abs(y)
.br
BLAS_CONJ_TRANS    y := alpha*abs(A\(aq)*abs(x) + beta*abs(y)
Unchanged on exit.
.TP 7
M      - INTEGER
On entry, M specifies the number of rows of the matrix A.
M must be at least zero.
Unchanged on exit.
.TP 7
N      - INTEGER
On entry, N specifies the number of columns of the matrix A.
N must be at least zero.
Unchanged on exit.
.TP 7
ALPHA  - REAL
On entry, ALPHA specifies the scalar alpha.
Unchanged on exit.
.TP 7
A      - COMPLEX          array of DIMENSION ( LDA, n )
Before entry, the leading m by n part of the array A must
contain the matrix of coefficients.
Unchanged on exit.
.TP 7
LDA    - INTEGER
On entry, LDA specifies the first dimension of A as declared
in the calling (sub) program. LDA must be at least
max( 1, m ).
Unchanged on exit.
.TP 7
X      - COMPLEX          array of DIMENSION at least
( 1 + ( n - 1 )*abs( INCX ) ) when TRANS = \(aqN\(aq or \(aqn\(aq
and at least
( 1 + ( m - 1 )*abs( INCX ) ) otherwise.
Before entry, the incremented array X must contain the
vector x.
Unchanged on exit.
.TP 7
INCX   - INTEGER
On entry, INCX specifies the increment for the elements of
X. INCX must not be zero.
Unchanged on exit.
.TP 7
BETA   - REAL
On entry, BETA specifies the scalar beta. When BETA is
supplied as zero then Y need not be set on input.
Unchanged on exit.
.TP 7
Y      - REAL             array of DIMENSION at least
( 1 + ( m - 1 )*abs( INCY ) ) when TRANS = \(aqN\(aq or \(aqn\(aq
and at least
( 1 + ( n - 1 )*abs( INCY ) ) otherwise.
Before entry with BETA non-zero, the incremented array Y
must contain the vector y. On exit, Y is overwritten by the
updated vector y.
.TP 7
INCY   - INTEGER
On entry, INCY specifies the increment for the elements of
Y. INCY must not be zero.
Unchanged on exit.
Level 2 Blas routine.
